The Qilian Mountain permafrost area located in the northern of Qinghai-Tibet Plateau is a favorable place for natural gas hydrate formation and enrichment,due to its well-developed fractures and abundant gas sources.U...The Qilian Mountain permafrost area located in the northern of Qinghai-Tibet Plateau is a favorable place for natural gas hydrate formation and enrichment,due to its well-developed fractures and abundant gas sources.Understanding the formation and distribution of multi-component gas hydrates in fractures is crucial in accurately evaluating the hydrate reservoir resources in this area.The hydrate formation experiments were carried out using the core samples drilled from hydrate-bearing sediments in Qilian Mountain permafrost area and the multi-component gas with similar composition to natural gas hydrates in Qilian Mountain permafrost area.The formation and distribution characteristics of multi-component gas hydrates in core samples were observed in situ by X-ray Computed Tomography(X-CT)under high pressure and low temperature conditions.Results show that hydrates are mainly formed and distributed in the fractures with good connectivity.The ratios of volume of hydrates formed in fractures to the volume of fractures are about 96.8%and 60.67%in two different core samples.This indicates that the fracture surface may act as a favorable reaction site for hydrate formation in core samples.Based on the field geological data and the experimental results,it is preliminarily estimated that the inventory of methane stored in the fractured gas hydrate in Qilian Mountain permafrost area is about 8.67×1013 m3,with a resource abundance of 8.67×108 m3/km2.This study demonstrates the great resource potential of fractured gas hydrate and also provides a new way to further understand the prospect of natural gas hydrate and other oil and gas resources in Qilian Mountain permafrost area.展开更多
The natural and economic conditions of agricultural resources vary greatly in China,especially in hilly and mountainous areas.The phenomenon of land fragmentation has become increasingly prominent,so that large-scale ...The natural and economic conditions of agricultural resources vary greatly in China,especially in hilly and mountainous areas.The phenomenon of land fragmentation has become increasingly prominent,so that large-scale operations cannot be fully achieved in a short period of time,and the centralized and continuous scale of operations cannot be realized in China.In addition,with increasingly strict farmland protection and agricultural land use control systems,the issues of nongrain production and nonagricultural cultivated land use have become increasingly restricted.Thus,it is quite necessary to determine the appropriate scale of operations and the means to achieve moderately scaled operations for the new business entities.On the basis of microsurvey data for 108 new citrus-planting business entities in the modern agricultural park in the Chongqing's Jiangjin District,an area with long citrus-planting history,we measured the moderate scale of new citrus-planting business entities to maximize profit using a translog growth model.According to the projection pursuit model,we evaluated the suitability conditions of citrus planting in garden land,woodland,grassland,and general cultivated land in the study area.We then explored the potential for new moderate-scale business entities within different farming radii.The results showed that large-scale planting conditions of citrus in garden land,forest land,grassland,and general cultivated land in the study area were suitable,and the proportion of high-suitable and mediumsuitable land was 73.42%.Under the existing social and economic conditions,the moderate scale of new citrus-planting business entities in the study area was 1.8–2.7 hm^(2).In particular,its rankings from large to small were agricultural enterprises(17.19–25.78 hm^(2)),farmer cooperatives(16.88–25.33 hm^(2)),big growers and breeders(6.39–9.59 hm^(2)),and family farms(5.02–7.53 hm^(2)).In the sample of 108 households,only 47.22%of the entities achieved moderate-scale operation,of which 25%of the entities achieved a scale greater than moderate operation.However,52.78%of the entities achieved a scale of less than moderate operation.These entities would have to transfer the surrounding adjacent garden land,forest land,grassland,or general cultivated land to achieve largescale land management.The land area of the adjacent gardens in a 1000 m farming radius could meet the moderate-scale operation demand of the vast majority of new business entities.For the vast majority of new business entities,the land area of the adjacent woodland,grassland,and general cultivated land could supplement the garden land to achieve moderate-scale operation in a 500 m farming radius.If the land area with moderate suitability and high suitability is prioritized,the land area in the adjacent gardens in the 1000 m farming radius could meet the moderate-scale operation demand for the vast majority of new business entities.Within the 500 m farming radius,the vast majority of new business entities have achieved moderate-scale operations if the land area adjacent to forest land,grassland,and general arable land was supplemented by gardens;however,a few entities could not achieve moderate-scale operations.From the village perspective,gardens were prioritized.Sixteen villages had planting areas and planting suitability that exceeded the average level of the study area,accounting for 23.53%.If combined with the reserve potential of the garden land,eight villages could improve their potential,accounting for 11.76%.Therefore,the conditions of large-scale citrus planting in the study area should be further improved,and the scale expansion of new citrus-planting business entities should receive additional scientific guidance.展开更多
Magnitude and distance of major potential source are needed in order to determine duration time of artificial ground motion and to determine the type of response spectrum (near field or far field) when using the seism...Magnitude and distance of major potential source are needed in order to determine duration time of artificial ground motion and to determine the type of response spectrum (near field or far field) when using the seismic intensity zonation map. The magnitude probabilistic distribution function of seismic belt and the magnitude and space joint distribution function for given intensity of the site in a potential Source are provided. Then the basicformula of calculating expected magnitude and expected distance are developed. Several examples for calculating expected magnitude and expected distance in northern China are discussed. These results show that expected magnitude and expected distance are related not only to geometry of potential source and magnitude but also to the intensity of the site with certain exceeding probability.展开更多
[Objective] The research aimed to study the first spring soaking rain weather and its precipitation enhancement potential forecast in Jinzhou area in 2010. [Method] From the weather situation characteristics, main inf...[Objective] The research aimed to study the first spring soaking rain weather and its precipitation enhancement potential forecast in Jinzhou area in 2010. [Method] From the weather situation characteristics, main influence system, forecast service, artificial precipitation enhancement operation and so on, the first spring soaking rain weather process in Jinzhou area in 2010 was summarized comprehensively. [Result] The weather situation characteristics of soaking rain were that the high-altitude cold air was weak, and the low-level warm wet airflow was obvious. The main influence systems were the high-altitude trough, the high-altitude shear line and the ground Mongolian cyclone. The ground inverted trough system advanced northward and got through with the same phase of Mongolian cyclone, which provided the certain energy and water vapor for the precipitation in Jinzhou area. It was one of key reasons for generating the soaking rain. The numerical forecast product played the certain guidance role in the forecast service work. The situation field forecast was accurate, but the precipitation forecast deviation was big. Therefore, the forecast service couldn’t depend on the numerical forecast product simply and totally, and should combine with the actual monitoring data to analyze and apply comprehensively. [Conclusion] The research played the safeguarding role in carrying out the large-scale artificial precipitation enhancement operation successfully in the whole area of Jinzhou.展开更多
Objective The Miao'ershan-Yuechengling composite granite, located in northern Guangxi at the western section of the Nanling Range, is a multi-period and multi-stage composite pluton with an exposed area of more than...Objective The Miao'ershan-Yuechengling composite granite, located in northern Guangxi at the western section of the Nanling Range, is a multi-period and multi-stage composite pluton with an exposed area of more than 3000 km2 (Fig. 1). Paleozoic and Proterozoic strata are exposed around it, and magmatic activities mainly occurred during the Caledonian and Indosinian periods. Till now, more than one hundred W-Sn-Mo-Pb-Zn-Cu (U) deposits and ore occurrences have been discovered along the inner and outer contact zones of this granite. Through recent years' research, we infer that this area is not only a preferred area for studying granite and mineralization in Caledonian and lndosinian periods, but also a potential Caledonian- lndosinian ore-concentrated area.展开更多
Lower Paleozoic carbonate rocks are an important exploration area in craton area of the Tarim Basin,with the proven oil and gas reserves of more than 2.2×10^8 t,but no large-scale discovery has been made in the G...Lower Paleozoic carbonate rocks are an important exploration area in craton area of the Tarim Basin,with the proven oil and gas reserves of more than 2.2×10^8 t,but no large-scale discovery has been made in the Gucheng area so far.The key issues restricting exploration are that the source rock,reservoir scale and law of oil and gas enrichment are unclear.By systematically examining the petroleum geological conditions of Lower Paleozoic carbonate rocks,the following findings are reached:(1)Source rocks of slope-basin facies developed in Cambrian-Lower Ordovician in the Gucheng area.(2)The dolomitized beach in the lower part of Ordovician Yingshan Formation has large-scale reservoirs,good reservoir-cap assemblage and developed gas source faults,and is an important field for increasing reserves and production in the near future;hydrocarbon enrichment is controlled by reservoir and gas source faults,and the central dolomitized beach zone is the main exploration area.(3)The Cambrian platform margin reef beach,large in scale,good in physical properties and close to source rocks,has the possibility to form monolithic gas field;the caprock and preservation conditions are the key factors for hydrocarbon enrichment;the northern part of the phasesⅠandⅡplatform margin reefs has better sealing conditions,and is the main direction of next exploration.(4)Limestone fault solution reservoirs in the upper part of Ordovician Yingshan Formation,controlled by faults and small in scale,but good in reservoir-cap combination,worth exploring.(5)The granular limestone beach of Ordovician Yijianfang Formation is well developed and gas-bearing,but short in exposure dissolution time,and the reservoirs are strongly heterogeneous,and are a potential exploration field.展开更多
The Sanjiang area is an important granite distribution area in China,except for South China,in which granites is complex and complete.Based on fully collecting date about it,this paper explores the significance of ura...The Sanjiang area is an important granite distribution area in China,except for South China,in which granites is complex and complete.Based on fully collecting date about it,this paper explores the significance of uranium展开更多
Deep geothermal resources mainly refer to the thermal energy stored in subsurface rocks and fluids therein at a depth of 3-10 km,which is a kind of renewable and sustainable clean energy unaffected by weather and seas...Deep geothermal resources mainly refer to the thermal energy stored in subsurface rocks and fluids therein at a depth of 3-10 km,which is a kind of renewable and sustainable clean energy unaffected by weather and seasonal changes.Large scale exploitation of the deep geothermal resources is of great significance to ensuring national energy security and achieving the“Carbon Peak and Carbon Neutrality”.Based on the latest terrestrial heat flow data,this paper estimated the potential of deep geothermal resources in the terrestrial areas of China,and the results show that the total amount of geothermal resources within 3e10 km under the Earth's surface in the terrestrial areas of China is 24.6×10^(15)GJ.In line with climate zones categorized,the geothermal resource proportion is 43.81%for severe cold regions,29.19%for cold regions,6.92%for mild regions,13.82%for hot summer and cold winter regions,and 6.26%for hot summer and warm winter regions.Statistics according to the burial depth range reveal that the resources within depth ranges of 3-5 km,5-7 km and 7-10 km under the Earth's surface are 4.3119×10^(15)GJ,6.37674×10^(15)GJ and 13.89594×10^(15)GJ respectively,showing an increasing trend of geothermal potential with increasing burial depth.The deep geothermal resources are mainly of medium-to-high temperature reserves,and the energy supply strategy can be optimized by combining the climate conditions and population distribution,as well as considering power generation.In regions of cold or severe cold climate,the geothermal resources may be applied to geothermal power generation and district heating in combination;in regions of hot summer and cold winter or mild climates,the resources can be used for geothermal power generation combined with cooling and heating;in regions of hot summer and warm winter climates,the resources may be applied to geothermal power generation combined with cooling and industrial and agricultural utilization.Exploitation of deep geothermal resources also can be combined with carbon dioxide sequestration,multi-mineral resources extraction and energy storage to realize comprehensive exploitation and utilization of various energy resources.It is suggested that theoretical technology research should be combined with pilot tests and field demonstrations,and large-scale economic exploitation of deep geothermal resources should be arranged in a coordinated manner,following the principles of overall planning and step-by-step implementation.展开更多
Dark mudstones and shales of the Carboniferous Jiusi Formation are widely developed in northern Guizhou and Yunnan provinces, SW China. However, the distribution, reservoir characterization, and exploration potential ...Dark mudstones and shales of the Carboniferous Jiusi Formation are widely developed in northern Guizhou and Yunnan provinces, SW China. However, the distribution, reservoir characterization, and exploration potential of organic-rich shales in this area are yet to be quantified, thus limiting the prospect of shale gas in this area. This study investigates the basic geological conditions of Jiusi shale gas, using core data, well-logs, and some other test data, obtaining the following results. The organic-rich shales are mainly composed of deltaic-to-shallow-shelf deposits, with thickness ranging from 0 to 450 m, and above 350 m around the subsidence center. The organic matter is mainly type Ⅱ kerogen with TOC content of mostly 1%–2%, indicating a moderate maturity. The argillaceous shale reservoirs are indicative of strong heterogeneity, high clay minerals content, low porosity, low permeability, high specific surface area, and relatively developed secondary porosity. The gas-log anomaly intervals obtained from the survey wells have a cumulative thickness that is apparently greater than 200 m, and a few shale intervals showing high desorbed and adsorbed gas contents. Due to complex structures in the study area, conditions responsible for shale gas occurrence and trapping are generally moderate. However, areas having wide and gentle folds with moderate depth of burial reveals relatively favorable conditions of hydrocarbon traps. In contrast with typical marine-continental transitional shales, the Jiusi shale have better geological conditions for shale gas preservation. The analysis of the geological framework and hydrocarbon potential of Carboniferous Jiusi Formation provide more insight for the exploration of Carboniferous shale gas in southern China.展开更多
In order to construct a newly developed green area, the Tanggu urban area as the core part of Binhai new area,needs more and more clean energy year by year. This area is abound in geothermal resources endowed by the g...In order to construct a newly developed green area, the Tanggu urban area as the core part of Binhai new area,needs more and more clean energy year by year. This area is abound in geothermal resources endowed by the grand Nature.Based on the estimation of展开更多
The study area is located in the Fars area (Interior Fars sub-basin). This area, which is part of the Zagros fold-thrust belt, is located in Zagros simple folded sub zone. It is known as one of the most important regi...The study area is located in the Fars area (Interior Fars sub-basin). This area, which is part of the Zagros fold-thrust belt, is located in Zagros simple folded sub zone. It is known as one of the most important regions in the world Gas rich. In this area, anticlinal folds are a different orientation of such as the North Western-South Eastern, East-West and North Eastern-South Western. The Karbasi and Khaftar anticlines are case study anticlines in the interior Fars sub-basin (Fassa area). The anticlines in the Fars region, which are located in the Zagros fold-thrust belt, are valuable because they possess several hydrocarbons. The main aim of this paper is evaluation of hydrocarbon potential in the Jahrom area (Interior Fars) based on interpretation of the Isopach maps and well data. This paper presents part of the results of a regional study of the Coastal Fars area in the Zagros Simply folded belt, based on original fieldwork, satellite images, structural sections, geological maps and well data. In order to investigate of periods Nezamabad fault activity, Isopach maps of the study area has been prepared based on well drilling data and the thickness of the drilled formations. In this study utilizes the thickness of the drilled formations in the study area, for each sedimentary unit was carried out to prepare Isopach maps. The Isopach map prepared based on GIS software method and exploration well data. The Nezamabad fault has been lacked of activity at the deposition time of the Dalan, Kangan, Dashtak, Fahliyan, Gadvan, Dariyan, Kazhdomi, Sarvak, Gurpi and Pabdeh formations within the Khaftar and Karbasi anticline area. Accordingly, changes in basin floor, at the time of sedimentation these formations has not been affected by the Nezamabad fault. Probably the Nezamabad fault has been activated during deposition of the Surmeh, Hith, Laffan and Ilam formations and in this area paleo-basin has been controlled by this fault. In other words, it seems that, activity of the Nezamabad fault in this area have been limited to Jurassic and Cretaceous periods (Coniacian and Senomanian). This can means that in this periods time, the Nezamabad fault have been active sedimentation along with tectonic processes and activities affected on thickness of the Surmeh, Hith, Laffan and Ilam formations. Finally, it seems that the Nezamabad Fault activity has been affected on the source rock, reservoir rock and cap rock and then controlled distributing of hydrocarbon System of the study area in the Khaftar and Karbasi as anticlinal oil traps.展开更多
Timor island has a tropical climate with relatively little rainfall and surface water is often not available throughout the year with groundwater relied on to fulfill daily domestic necessities. Geological reconnaissa...Timor island has a tropical climate with relatively little rainfall and surface water is often not available throughout the year with groundwater relied on to fulfill daily domestic necessities. Geological reconnaissance mapping, hydrogeological investigation, and resistivity survey were undertaken in this study to systematically understand the hydrogeologic system (e.g., aquifer system, hydrostratigraphic units, groundwater flow direction) and its potentiality for water supply to human consumption in Alaua Kraik area, Baucau Municipality, Timor-Leste. Res2DInv, Dips 5.1, Surfer 16, Global Mapper 13, and ArcGIS 10.6 software was used to create geological reconnaissance maps, resistivity interpretation profile lines, and a hydrostratigraphic model. Rainfall precipitation, rainfall intensity, maximum rate of runoff and infiltration data are also used to interpret the groundwater potential in the study area. Two rock units occur in the study area;permeable alluvial deposits which unconformable overlie impermeable interbedded red marl-chert and calcareous shale. Structurally the area comprises the Lacamutu anticline, thrust fault, left slip fault, and normal right slip fault. Resistivity lines indicate three (3) types of lithologies: alluvial deposit, an intercalated layer of red marl-chert, calcareous shale and wet calcareous shale. The alluvial deposit and red marl-chert layer intercalated with calcareous shale units are classified as a hydrostratigraphic unit of intergranular and localised aquifer systems with low productivity. The groundwater flows through the existing fractures of the shear joint and tends to flow towards the left slip fault plane zone from the North to South direction. Much of the rainwater in the study area is most likely intercepted, evaporated, and or transpiration as opposed to running off and infiltrating into the ground. The permeable and heavily fractured impermeable rock units in the study area have good porosity but low permeability and represent poor aquifers. The springs and Lacamutu River have low discharge and are generally dry in the dry season as it does not have an adequate aquifer that can accumulate and pass groundwater with significant volumes even if the rainfall in the study area is classified as moderate rainfall.展开更多
Five principles and methods are proposed for estimating the maximum potential earthquakesin low seismicity areas,and their applicabilities are discussed,taking Sichuan basin as asample area.The proposed principles and...Five principles and methods are proposed for estimating the maximum potential earthquakesin low seismicity areas,and their applicabilities are discussed,taking Sichuan basin as asample area.The proposed principles and methods are not only on the grounds of thegeological tectonics but also considered fully the mutual complementation between geologicaland seismological methods.They will be helpful to the study of engineering seismology andthe assessment of designing ground motion parameters in low seismicity areas.展开更多
Michoacán has a deforested area of 525,260 ha, representing 52,526 ha per year, mainly caused by anthropogenic disturbances such as agricultural burning and forest fires (50%), change of use of land for extensive...Michoacán has a deforested area of 525,260 ha, representing 52,526 ha per year, mainly caused by anthropogenic disturbances such as agricultural burning and forest fires (50%), change of use of land for extensive livestock farming (28%), agriculture (17%) and illegal logging (5%). The establishment of forest plantations is an alternative for reducing the pressure on natural forests and creating options for sustainable development and diversification of production and conversion of land for agricultural and livestock fragmented for forestry purposes. The aim of this study was to determine the potential areas for commercial forest plantations of Enterolobium cyclocarpum (Jacq.) Griseb. in the State of Michoacán, México, through the use of Geographic information systems (GIS). Areas were identified using IDRISI 32, and ArcView software. Screening variables include annual temperature, annual precipitation, land use, soil type, elevation and slope. Products obtained were field verified. Two maps where potential areas for the establishment of commercial forest plantations of E. cyclocarpum shown were obtained. Potential areas for commercial forest plantation establishment are (0% - 15% slope) for commercial forest plantations mechanized was 57,227 ha and (15% - 30% slope) for manual plantations was 6273 ha. The total area in the state with potential for the establishment of the species in the study was 63,500 ha.展开更多
The targeted area for plant reforestation in the state of Michoacan is made up of eroded areas and pasture induced areas, both adding to 525,260 ha and representing 10.9% of the total surface of the state. The regions...The targeted area for plant reforestation in the state of Michoacan is made up of eroded areas and pasture induced areas, both adding to 525,260 ha and representing 10.9% of the total surface of the state. The regions with the largest areas in need of reforestation are the Costa with 185,396 ha (29%), Oriente with 106,836 (17%) and Tierra Caliente with 96,284 (15%). Commercial forest plantations are an alternative for reducing the pressure on natural forests and creating options for sustainable and diversified development, changing the land use from fragmented agricultur and livestock purposes to forestry. The object of this study was to determine potential areas for the establishment of commercial forest plantations of Tabebuia rosea (Bertol.) DC. in the state of Michoacan, Mexico, by using geographic information systems. The outlining of potential areas was performed with the IDRISI 32 and ArcView programs, according to the environmental requirements of T. rosea. These environmental requirements include precipitation, temperature, soil, altitude, land use and slope. The analysis resulted in two maps where the potential areas for the establishment of commercial forest plantations with this species were shown, which turned out a total potential area of 54,320 ha, distributed in 47,566 ha considering a slope of 0% - 15% for non-manual forest plantations, and 6754 ha considering a slope of 15% - 30% for manual forest plantations. The ecologic conditions in Michoacan are favorable for successful establishment and development of commercial forest plantations of T. rosea.展开更多
The characteristics of seismogenic structures are an important basis for delineating the potential seismic source areas and determining the annual occurrence rate of earthquakes. The potential seismic source area does...The characteristics of seismogenic structures are an important basis for delineating the potential seismic source areas and determining the annual occurrence rate of earthquakes. The potential seismic source area does not only have the intension that “this area has the possibility for destructive earthquakes to occur in the future" but also means that earthquakes of high magnitude interval have the characteristics of similar recurrence. When determining the seismic activity parameters of a statistical unit, some active tectonic blocks in the unit may have different background earthquakes. In order to better reflect the heterogeneity in space of seismic activities, it is necessary to divide the potential seismic source areas into three orders. By analyzing the recurrence characteristics of earthquakes of high magnitude interval in the potential source area and calculating the occurrence probability of earthquakes of high magnitude interval in the potential seismic source area in the time window for prediction, the average annual occurrence rate of earthquakes can be obtained by the method of probability equivalent conversion in the time window for prediction. This would be helpful for considering the recurrence characteristics of strong earthquakes in potential source areas within the framework of seismic risk analysis of China. Besides, the insufficient frequency of characteristic earthquakes of the next high magnitude interval in the potential source area and the heterogeneity of strong earthquakes on seismogenic structures are analyzed to see their application in seismic risk analysis.展开更多
As an important element of urban renewal in highly urbanized areas, pocket parks with small size, flexible layout and daily accessibility are becoming a major component of green infrastructure and the mainstay of outd...As an important element of urban renewal in highly urbanized areas, pocket parks with small size, flexible layout and daily accessibility are becoming a major component of green infrastructure and the mainstay of outdoor recreation space expansion in high-density urban centers. Nevertheless, the absence of a comprehensive framework for evaluating the potential of pocket park construction (PPC), one that integrates diverse influencing factors on a macro scale, has resulted in the random installation of such spaces, often failing to optimize the utilization of urban land. Addressing this critical lacuna, we propose an approach to evaluate PPC potential from a city-scale perspective, which is used to support the determination of which land units should be prioritized for PPC. A complete and feasible workflow was also established to identify potential land units, construct an index system for PPC combining demand and supply levels, quantitatively calculate indices based on remote sensing (RS) and geographic information system (GIS), accurately evaluate PPC potential using an entropy-weighted TOPSIS model, and develop targeted renewal strategies. A case study in Dalian, China, demonstrated the applicability and implications of the workflow. The results showed that it is flexible and easy to adapt to different local contexts, allowing evaluators to introduce parameters considering the availability of local data, and will help decision makers to build pocket parks in the most effective plots, providing a strong reference for high-quality development in other high-density urban centers facing the contradiction between ecological construction and land scarcity.展开更多
Experiments were performed on 64 Sprague-Dawley rats under ure-thane anesthesia. Extracellular recording method was used to investigate the effect of aluminum (Al)microinjected into CA3 on long-term potentiation (LTP)...Experiments were performed on 64 Sprague-Dawley rats under ure-thane anesthesia. Extracellular recording method was used to investigate the effect of aluminum (Al)microinjected into CA3 on long-term potentiation (LTP) in this area. The relationship between the inhibitory effect of Al and L-arginine-NO pathway was also studied. Microinjection of Al (0. 5 mol/L, 1 μl ) into CA3 could block the induction of LTP in CA3. Microinjection of Al (0. 5 mol/L, 1 μl) into CA3 after LTP was induced could also decrease the amplitude of population spike (PS). The inhibitory effect of Al on LTP in CA3 could be enhanced by preinjection of NG-nitro-L-arginine (0. 3 mol/L, 1 μl). Preinjection of L-arginine (0. 3 mol/L, 1 μl) into CA3 could antagonize the inhibitory effect of Al on LTP. These results suggest that Al could block the induction of LTP and decrease the amplitude of PS potentiated in CA3. The effect of Al might be antagonized by L-arginine-NO pathway.展开更多
Continental shale oil is a general term for liquid hydrocarbons and many kinds of organic matter in continental organic-rich shale series with vitrinite reflectance of more than 0.5%at buried depth of more than 300 m,...Continental shale oil is a general term for liquid hydrocarbons and many kinds of organic matter in continental organic-rich shale series with vitrinite reflectance of more than 0.5%at buried depth of more than 300 m,and is an important type of source-rock oil and gas.Based on the evolution model of oil generation and expulsion in organic-rich shale series controlled by maturity,continental shale oil is divided into two types:medium-high maturity and medium-low maturity.(1)The continental shale series in China develop high-quality source rocks of freshwater and saltwater lacustrine facies,as well as multiple types of reservoirs,including clastic rocks,carbonate rocks,diamictite,tuff and shale,forming a number of"sweet sections"and"sweet areas"of continuous distribution inside or near source rocks,which have large scale resources.(2)Experimental analysis of organic rich shale samples shows that the shale samples with wavy and horizontal beddings have good storage conditions,and the horizontal permeability of shale is tens to hundreds of times of its vertical permeability,which is conducive to the lateral migration and accumulation of shale oil in the source rocks.(3)After evaluation,the geological resources of medium-high maturity shale oil are about 10 billion tons,which can be effectively developed by horizontal drilling and volumetric fracturing,and will be a practical field of oil exploration in recent years.Shale oil with medium and low maturity has huge resource potential,and technological recoverable resources of(70?90)billion tons,making it a strategic alternative resource of oil industry.However,economic development of this type of shale oil needs in-situ conversion technology breakthroughs.Continental shale oil is an inevitable choice in the process of Chinese continental petroleum exploration from"outside source"to"inside source".Making breakthroughs in the core technologies such as"sweet area"evaluation and optimization,horizontal well volume fracturing and in-situ conversion technology and equipment is the key to realizing scale development of continental shale oil economically.展开更多
基金the financial support of the National Natural Science Foundation of China(42176212,41976074 and 41302034)the Marine S&T Fund of Shandong Province for Laoshan Laboratory(2021QNLM020002)the Marine Geological Survey Program(DD20221704)。
文摘The Qilian Mountain permafrost area located in the northern of Qinghai-Tibet Plateau is a favorable place for natural gas hydrate formation and enrichment,due to its well-developed fractures and abundant gas sources.Understanding the formation and distribution of multi-component gas hydrates in fractures is crucial in accurately evaluating the hydrate reservoir resources in this area.The hydrate formation experiments were carried out using the core samples drilled from hydrate-bearing sediments in Qilian Mountain permafrost area and the multi-component gas with similar composition to natural gas hydrates in Qilian Mountain permafrost area.The formation and distribution characteristics of multi-component gas hydrates in core samples were observed in situ by X-ray Computed Tomography(X-CT)under high pressure and low temperature conditions.Results show that hydrates are mainly formed and distributed in the fractures with good connectivity.The ratios of volume of hydrates formed in fractures to the volume of fractures are about 96.8%and 60.67%in two different core samples.This indicates that the fracture surface may act as a favorable reaction site for hydrate formation in core samples.Based on the field geological data and the experimental results,it is preliminarily estimated that the inventory of methane stored in the fractured gas hydrate in Qilian Mountain permafrost area is about 8.67×1013 m3,with a resource abundance of 8.67×108 m3/km2.This study demonstrates the great resource potential of fractured gas hydrate and also provides a new way to further understand the prospect of natural gas hydrate and other oil and gas resources in Qilian Mountain permafrost area.
基金supported by National Natural Science Foundation of China(No.41971244)National Natural Science Foundation of China(No.41501104)Natural Science Foundation of Chongqing Municipal Science and Technology Commission(cstc2021jcyj-msxm X0696)。
文摘The natural and economic conditions of agricultural resources vary greatly in China,especially in hilly and mountainous areas.The phenomenon of land fragmentation has become increasingly prominent,so that large-scale operations cannot be fully achieved in a short period of time,and the centralized and continuous scale of operations cannot be realized in China.In addition,with increasingly strict farmland protection and agricultural land use control systems,the issues of nongrain production and nonagricultural cultivated land use have become increasingly restricted.Thus,it is quite necessary to determine the appropriate scale of operations and the means to achieve moderately scaled operations for the new business entities.On the basis of microsurvey data for 108 new citrus-planting business entities in the modern agricultural park in the Chongqing's Jiangjin District,an area with long citrus-planting history,we measured the moderate scale of new citrus-planting business entities to maximize profit using a translog growth model.According to the projection pursuit model,we evaluated the suitability conditions of citrus planting in garden land,woodland,grassland,and general cultivated land in the study area.We then explored the potential for new moderate-scale business entities within different farming radii.The results showed that large-scale planting conditions of citrus in garden land,forest land,grassland,and general cultivated land in the study area were suitable,and the proportion of high-suitable and mediumsuitable land was 73.42%.Under the existing social and economic conditions,the moderate scale of new citrus-planting business entities in the study area was 1.8–2.7 hm^(2).In particular,its rankings from large to small were agricultural enterprises(17.19–25.78 hm^(2)),farmer cooperatives(16.88–25.33 hm^(2)),big growers and breeders(6.39–9.59 hm^(2)),and family farms(5.02–7.53 hm^(2)).In the sample of 108 households,only 47.22%of the entities achieved moderate-scale operation,of which 25%of the entities achieved a scale greater than moderate operation.However,52.78%of the entities achieved a scale of less than moderate operation.These entities would have to transfer the surrounding adjacent garden land,forest land,grassland,or general cultivated land to achieve largescale land management.The land area of the adjacent gardens in a 1000 m farming radius could meet the moderate-scale operation demand of the vast majority of new business entities.For the vast majority of new business entities,the land area of the adjacent woodland,grassland,and general cultivated land could supplement the garden land to achieve moderate-scale operation in a 500 m farming radius.If the land area with moderate suitability and high suitability is prioritized,the land area in the adjacent gardens in the 1000 m farming radius could meet the moderate-scale operation demand for the vast majority of new business entities.Within the 500 m farming radius,the vast majority of new business entities have achieved moderate-scale operations if the land area adjacent to forest land,grassland,and general arable land was supplemented by gardens;however,a few entities could not achieve moderate-scale operations.From the village perspective,gardens were prioritized.Sixteen villages had planting areas and planting suitability that exceeded the average level of the study area,accounting for 23.53%.If combined with the reserve potential of the garden land,eight villages could improve their potential,accounting for 11.76%.Therefore,the conditions of large-scale citrus planting in the study area should be further improved,and the scale expansion of new citrus-planting business entities should receive additional scientific guidance.
文摘Magnitude and distance of major potential source are needed in order to determine duration time of artificial ground motion and to determine the type of response spectrum (near field or far field) when using the seismic intensity zonation map. The magnitude probabilistic distribution function of seismic belt and the magnitude and space joint distribution function for given intensity of the site in a potential Source are provided. Then the basicformula of calculating expected magnitude and expected distance are developed. Several examples for calculating expected magnitude and expected distance in northern China are discussed. These results show that expected magnitude and expected distance are related not only to geometry of potential source and magnitude but also to the intensity of the site with certain exceeding probability.
文摘[Objective] The research aimed to study the first spring soaking rain weather and its precipitation enhancement potential forecast in Jinzhou area in 2010. [Method] From the weather situation characteristics, main influence system, forecast service, artificial precipitation enhancement operation and so on, the first spring soaking rain weather process in Jinzhou area in 2010 was summarized comprehensively. [Result] The weather situation characteristics of soaking rain were that the high-altitude cold air was weak, and the low-level warm wet airflow was obvious. The main influence systems were the high-altitude trough, the high-altitude shear line and the ground Mongolian cyclone. The ground inverted trough system advanced northward and got through with the same phase of Mongolian cyclone, which provided the certain energy and water vapor for the precipitation in Jinzhou area. It was one of key reasons for generating the soaking rain. The numerical forecast product played the certain guidance role in the forecast service work. The situation field forecast was accurate, but the precipitation forecast deviation was big. Therefore, the forecast service couldn’t depend on the numerical forecast product simply and totally, and should combine with the actual monitoring data to analyze and apply comprehensively. [Conclusion] The research played the safeguarding role in carrying out the large-scale artificial precipitation enhancement operation successfully in the whole area of Jinzhou.
基金supported by the National Natural Science Foundation of China(grants No.41572058 and 41672065)
文摘Objective The Miao'ershan-Yuechengling composite granite, located in northern Guangxi at the western section of the Nanling Range, is a multi-period and multi-stage composite pluton with an exposed area of more than 3000 km2 (Fig. 1). Paleozoic and Proterozoic strata are exposed around it, and magmatic activities mainly occurred during the Caledonian and Indosinian periods. Till now, more than one hundred W-Sn-Mo-Pb-Zn-Cu (U) deposits and ore occurrences have been discovered along the inner and outer contact zones of this granite. Through recent years' research, we infer that this area is not only a preferred area for studying granite and mineralization in Caledonian and lndosinian periods, but also a potential Caledonian- lndosinian ore-concentrated area.
基金Supported by the China National Science and Technology Major Project(2016E-0204).
文摘Lower Paleozoic carbonate rocks are an important exploration area in craton area of the Tarim Basin,with the proven oil and gas reserves of more than 2.2×10^8 t,but no large-scale discovery has been made in the Gucheng area so far.The key issues restricting exploration are that the source rock,reservoir scale and law of oil and gas enrichment are unclear.By systematically examining the petroleum geological conditions of Lower Paleozoic carbonate rocks,the following findings are reached:(1)Source rocks of slope-basin facies developed in Cambrian-Lower Ordovician in the Gucheng area.(2)The dolomitized beach in the lower part of Ordovician Yingshan Formation has large-scale reservoirs,good reservoir-cap assemblage and developed gas source faults,and is an important field for increasing reserves and production in the near future;hydrocarbon enrichment is controlled by reservoir and gas source faults,and the central dolomitized beach zone is the main exploration area.(3)The Cambrian platform margin reef beach,large in scale,good in physical properties and close to source rocks,has the possibility to form monolithic gas field;the caprock and preservation conditions are the key factors for hydrocarbon enrichment;the northern part of the phasesⅠandⅡplatform margin reefs has better sealing conditions,and is the main direction of next exploration.(4)Limestone fault solution reservoirs in the upper part of Ordovician Yingshan Formation,controlled by faults and small in scale,but good in reservoir-cap combination,worth exploring.(5)The granular limestone beach of Ordovician Yijianfang Formation is well developed and gas-bearing,but short in exposure dissolution time,and the reservoirs are strongly heterogeneous,and are a potential exploration field.
基金the China Nuclear Industry Geological Bureau Project (Grant No. 201637,201638)
文摘The Sanjiang area is an important granite distribution area in China,except for South China,in which granites is complex and complete.Based on fully collecting date about it,this paper explores the significance of uranium
基金supported by the Joint Petrochemical Fund project of National Natural Science Foundation of China”Deep Geological Processes and Resource Effects in the Basin”(Fund No.U20B6001).
文摘Deep geothermal resources mainly refer to the thermal energy stored in subsurface rocks and fluids therein at a depth of 3-10 km,which is a kind of renewable and sustainable clean energy unaffected by weather and seasonal changes.Large scale exploitation of the deep geothermal resources is of great significance to ensuring national energy security and achieving the“Carbon Peak and Carbon Neutrality”.Based on the latest terrestrial heat flow data,this paper estimated the potential of deep geothermal resources in the terrestrial areas of China,and the results show that the total amount of geothermal resources within 3e10 km under the Earth's surface in the terrestrial areas of China is 24.6×10^(15)GJ.In line with climate zones categorized,the geothermal resource proportion is 43.81%for severe cold regions,29.19%for cold regions,6.92%for mild regions,13.82%for hot summer and cold winter regions,and 6.26%for hot summer and warm winter regions.Statistics according to the burial depth range reveal that the resources within depth ranges of 3-5 km,5-7 km and 7-10 km under the Earth's surface are 4.3119×10^(15)GJ,6.37674×10^(15)GJ and 13.89594×10^(15)GJ respectively,showing an increasing trend of geothermal potential with increasing burial depth.The deep geothermal resources are mainly of medium-to-high temperature reserves,and the energy supply strategy can be optimized by combining the climate conditions and population distribution,as well as considering power generation.In regions of cold or severe cold climate,the geothermal resources may be applied to geothermal power generation and district heating in combination;in regions of hot summer and cold winter or mild climates,the resources can be used for geothermal power generation combined with cooling and heating;in regions of hot summer and warm winter climates,the resources may be applied to geothermal power generation combined with cooling and industrial and agricultural utilization.Exploitation of deep geothermal resources also can be combined with carbon dioxide sequestration,multi-mineral resources extraction and energy storage to realize comprehensive exploitation and utilization of various energy resources.It is suggested that theoretical technology research should be combined with pilot tests and field demonstrations,and large-scale economic exploitation of deep geothermal resources should be arranged in a coordinated manner,following the principles of overall planning and step-by-step implementation.
基金supported by National Science and Technology Major Project entitled Test and Application Promotion of Shale Gas Exploration and Evaluation Techniques(No.2016ZX05034)a project organized by the China Geological Survey entitled Shale Gas Geological Survey in Northeastern Yunnan(No.DD20190080).
文摘Dark mudstones and shales of the Carboniferous Jiusi Formation are widely developed in northern Guizhou and Yunnan provinces, SW China. However, the distribution, reservoir characterization, and exploration potential of organic-rich shales in this area are yet to be quantified, thus limiting the prospect of shale gas in this area. This study investigates the basic geological conditions of Jiusi shale gas, using core data, well-logs, and some other test data, obtaining the following results. The organic-rich shales are mainly composed of deltaic-to-shallow-shelf deposits, with thickness ranging from 0 to 450 m, and above 350 m around the subsidence center. The organic matter is mainly type Ⅱ kerogen with TOC content of mostly 1%–2%, indicating a moderate maturity. The argillaceous shale reservoirs are indicative of strong heterogeneity, high clay minerals content, low porosity, low permeability, high specific surface area, and relatively developed secondary porosity. The gas-log anomaly intervals obtained from the survey wells have a cumulative thickness that is apparently greater than 200 m, and a few shale intervals showing high desorbed and adsorbed gas contents. Due to complex structures in the study area, conditions responsible for shale gas occurrence and trapping are generally moderate. However, areas having wide and gentle folds with moderate depth of burial reveals relatively favorable conditions of hydrocarbon traps. In contrast with typical marine-continental transitional shales, the Jiusi shale have better geological conditions for shale gas preservation. The analysis of the geological framework and hydrocarbon potential of Carboniferous Jiusi Formation provide more insight for the exploration of Carboniferous shale gas in southern China.
文摘In order to construct a newly developed green area, the Tanggu urban area as the core part of Binhai new area,needs more and more clean energy year by year. This area is abound in geothermal resources endowed by the grand Nature.Based on the estimation of
文摘The study area is located in the Fars area (Interior Fars sub-basin). This area, which is part of the Zagros fold-thrust belt, is located in Zagros simple folded sub zone. It is known as one of the most important regions in the world Gas rich. In this area, anticlinal folds are a different orientation of such as the North Western-South Eastern, East-West and North Eastern-South Western. The Karbasi and Khaftar anticlines are case study anticlines in the interior Fars sub-basin (Fassa area). The anticlines in the Fars region, which are located in the Zagros fold-thrust belt, are valuable because they possess several hydrocarbons. The main aim of this paper is evaluation of hydrocarbon potential in the Jahrom area (Interior Fars) based on interpretation of the Isopach maps and well data. This paper presents part of the results of a regional study of the Coastal Fars area in the Zagros Simply folded belt, based on original fieldwork, satellite images, structural sections, geological maps and well data. In order to investigate of periods Nezamabad fault activity, Isopach maps of the study area has been prepared based on well drilling data and the thickness of the drilled formations. In this study utilizes the thickness of the drilled formations in the study area, for each sedimentary unit was carried out to prepare Isopach maps. The Isopach map prepared based on GIS software method and exploration well data. The Nezamabad fault has been lacked of activity at the deposition time of the Dalan, Kangan, Dashtak, Fahliyan, Gadvan, Dariyan, Kazhdomi, Sarvak, Gurpi and Pabdeh formations within the Khaftar and Karbasi anticline area. Accordingly, changes in basin floor, at the time of sedimentation these formations has not been affected by the Nezamabad fault. Probably the Nezamabad fault has been activated during deposition of the Surmeh, Hith, Laffan and Ilam formations and in this area paleo-basin has been controlled by this fault. In other words, it seems that, activity of the Nezamabad fault in this area have been limited to Jurassic and Cretaceous periods (Coniacian and Senomanian). This can means that in this periods time, the Nezamabad fault have been active sedimentation along with tectonic processes and activities affected on thickness of the Surmeh, Hith, Laffan and Ilam formations. Finally, it seems that the Nezamabad Fault activity has been affected on the source rock, reservoir rock and cap rock and then controlled distributing of hydrocarbon System of the study area in the Khaftar and Karbasi as anticlinal oil traps.
文摘Timor island has a tropical climate with relatively little rainfall and surface water is often not available throughout the year with groundwater relied on to fulfill daily domestic necessities. Geological reconnaissance mapping, hydrogeological investigation, and resistivity survey were undertaken in this study to systematically understand the hydrogeologic system (e.g., aquifer system, hydrostratigraphic units, groundwater flow direction) and its potentiality for water supply to human consumption in Alaua Kraik area, Baucau Municipality, Timor-Leste. Res2DInv, Dips 5.1, Surfer 16, Global Mapper 13, and ArcGIS 10.6 software was used to create geological reconnaissance maps, resistivity interpretation profile lines, and a hydrostratigraphic model. Rainfall precipitation, rainfall intensity, maximum rate of runoff and infiltration data are also used to interpret the groundwater potential in the study area. Two rock units occur in the study area;permeable alluvial deposits which unconformable overlie impermeable interbedded red marl-chert and calcareous shale. Structurally the area comprises the Lacamutu anticline, thrust fault, left slip fault, and normal right slip fault. Resistivity lines indicate three (3) types of lithologies: alluvial deposit, an intercalated layer of red marl-chert, calcareous shale and wet calcareous shale. The alluvial deposit and red marl-chert layer intercalated with calcareous shale units are classified as a hydrostratigraphic unit of intergranular and localised aquifer systems with low productivity. The groundwater flows through the existing fractures of the shear joint and tends to flow towards the left slip fault plane zone from the North to South direction. Much of the rainwater in the study area is most likely intercepted, evaporated, and or transpiration as opposed to running off and infiltrating into the ground. The permeable and heavily fractured impermeable rock units in the study area have good porosity but low permeability and represent poor aquifers. The springs and Lacamutu River have low discharge and are generally dry in the dry season as it does not have an adequate aquifer that can accumulate and pass groundwater with significant volumes even if the rainfall in the study area is classified as moderate rainfall.
基金This project was sponsored by the Joint Earthquake Science Foundation,China.Contribution No.99AC1021,Institute of Geophysics,CSB,China
文摘Five principles and methods are proposed for estimating the maximum potential earthquakesin low seismicity areas,and their applicabilities are discussed,taking Sichuan basin as asample area.The proposed principles and methods are not only on the grounds of thegeological tectonics but also considered fully the mutual complementation between geologicaland seismological methods.They will be helpful to the study of engineering seismology andthe assessment of designing ground motion parameters in low seismicity areas.
文摘Michoacán has a deforested area of 525,260 ha, representing 52,526 ha per year, mainly caused by anthropogenic disturbances such as agricultural burning and forest fires (50%), change of use of land for extensive livestock farming (28%), agriculture (17%) and illegal logging (5%). The establishment of forest plantations is an alternative for reducing the pressure on natural forests and creating options for sustainable development and diversification of production and conversion of land for agricultural and livestock fragmented for forestry purposes. The aim of this study was to determine the potential areas for commercial forest plantations of Enterolobium cyclocarpum (Jacq.) Griseb. in the State of Michoacán, México, through the use of Geographic information systems (GIS). Areas were identified using IDRISI 32, and ArcView software. Screening variables include annual temperature, annual precipitation, land use, soil type, elevation and slope. Products obtained were field verified. Two maps where potential areas for the establishment of commercial forest plantations of E. cyclocarpum shown were obtained. Potential areas for commercial forest plantation establishment are (0% - 15% slope) for commercial forest plantations mechanized was 57,227 ha and (15% - 30% slope) for manual plantations was 6273 ha. The total area in the state with potential for the establishment of the species in the study was 63,500 ha.
文摘The targeted area for plant reforestation in the state of Michoacan is made up of eroded areas and pasture induced areas, both adding to 525,260 ha and representing 10.9% of the total surface of the state. The regions with the largest areas in need of reforestation are the Costa with 185,396 ha (29%), Oriente with 106,836 (17%) and Tierra Caliente with 96,284 (15%). Commercial forest plantations are an alternative for reducing the pressure on natural forests and creating options for sustainable and diversified development, changing the land use from fragmented agricultur and livestock purposes to forestry. The object of this study was to determine potential areas for the establishment of commercial forest plantations of Tabebuia rosea (Bertol.) DC. in the state of Michoacan, Mexico, by using geographic information systems. The outlining of potential areas was performed with the IDRISI 32 and ArcView programs, according to the environmental requirements of T. rosea. These environmental requirements include precipitation, temperature, soil, altitude, land use and slope. The analysis resulted in two maps where the potential areas for the establishment of commercial forest plantations with this species were shown, which turned out a total potential area of 54,320 ha, distributed in 47,566 ha considering a slope of 0% - 15% for non-manual forest plantations, and 6754 ha considering a slope of 15% - 30% for manual forest plantations. The ecologic conditions in Michoacan are favorable for successful establishment and development of commercial forest plantations of T. rosea.
文摘The characteristics of seismogenic structures are an important basis for delineating the potential seismic source areas and determining the annual occurrence rate of earthquakes. The potential seismic source area does not only have the intension that “this area has the possibility for destructive earthquakes to occur in the future" but also means that earthquakes of high magnitude interval have the characteristics of similar recurrence. When determining the seismic activity parameters of a statistical unit, some active tectonic blocks in the unit may have different background earthquakes. In order to better reflect the heterogeneity in space of seismic activities, it is necessary to divide the potential seismic source areas into three orders. By analyzing the recurrence characteristics of earthquakes of high magnitude interval in the potential source area and calculating the occurrence probability of earthquakes of high magnitude interval in the potential seismic source area in the time window for prediction, the average annual occurrence rate of earthquakes can be obtained by the method of probability equivalent conversion in the time window for prediction. This would be helpful for considering the recurrence characteristics of strong earthquakes in potential source areas within the framework of seismic risk analysis of China. Besides, the insufficient frequency of characteristic earthquakes of the next high magnitude interval in the potential source area and the heterogeneity of strong earthquakes on seismogenic structures are analyzed to see their application in seismic risk analysis.
基金This study was supported by the National Natural Science Foundation of China(Grant No.52208045).
文摘As an important element of urban renewal in highly urbanized areas, pocket parks with small size, flexible layout and daily accessibility are becoming a major component of green infrastructure and the mainstay of outdoor recreation space expansion in high-density urban centers. Nevertheless, the absence of a comprehensive framework for evaluating the potential of pocket park construction (PPC), one that integrates diverse influencing factors on a macro scale, has resulted in the random installation of such spaces, often failing to optimize the utilization of urban land. Addressing this critical lacuna, we propose an approach to evaluate PPC potential from a city-scale perspective, which is used to support the determination of which land units should be prioritized for PPC. A complete and feasible workflow was also established to identify potential land units, construct an index system for PPC combining demand and supply levels, quantitatively calculate indices based on remote sensing (RS) and geographic information system (GIS), accurately evaluate PPC potential using an entropy-weighted TOPSIS model, and develop targeted renewal strategies. A case study in Dalian, China, demonstrated the applicability and implications of the workflow. The results showed that it is flexible and easy to adapt to different local contexts, allowing evaluators to introduce parameters considering the availability of local data, and will help decision makers to build pocket parks in the most effective plots, providing a strong reference for high-quality development in other high-density urban centers facing the contradiction between ecological construction and land scarcity.
基金This project was supported by grant from the National Nature Science Foundation of China (No.39270591)
文摘Experiments were performed on 64 Sprague-Dawley rats under ure-thane anesthesia. Extracellular recording method was used to investigate the effect of aluminum (Al)microinjected into CA3 on long-term potentiation (LTP) in this area. The relationship between the inhibitory effect of Al and L-arginine-NO pathway was also studied. Microinjection of Al (0. 5 mol/L, 1 μl ) into CA3 could block the induction of LTP in CA3. Microinjection of Al (0. 5 mol/L, 1 μl) into CA3 after LTP was induced could also decrease the amplitude of population spike (PS). The inhibitory effect of Al on LTP in CA3 could be enhanced by preinjection of NG-nitro-L-arginine (0. 3 mol/L, 1 μl). Preinjection of L-arginine (0. 3 mol/L, 1 μl) into CA3 could antagonize the inhibitory effect of Al on LTP. These results suggest that Al could block the induction of LTP and decrease the amplitude of PS potentiated in CA3. The effect of Al might be antagonized by L-arginine-NO pathway.
基金Supported by the China National Science and Technology Major Project(2016ZX05046)
文摘Continental shale oil is a general term for liquid hydrocarbons and many kinds of organic matter in continental organic-rich shale series with vitrinite reflectance of more than 0.5%at buried depth of more than 300 m,and is an important type of source-rock oil and gas.Based on the evolution model of oil generation and expulsion in organic-rich shale series controlled by maturity,continental shale oil is divided into two types:medium-high maturity and medium-low maturity.(1)The continental shale series in China develop high-quality source rocks of freshwater and saltwater lacustrine facies,as well as multiple types of reservoirs,including clastic rocks,carbonate rocks,diamictite,tuff and shale,forming a number of"sweet sections"and"sweet areas"of continuous distribution inside or near source rocks,which have large scale resources.(2)Experimental analysis of organic rich shale samples shows that the shale samples with wavy and horizontal beddings have good storage conditions,and the horizontal permeability of shale is tens to hundreds of times of its vertical permeability,which is conducive to the lateral migration and accumulation of shale oil in the source rocks.(3)After evaluation,the geological resources of medium-high maturity shale oil are about 10 billion tons,which can be effectively developed by horizontal drilling and volumetric fracturing,and will be a practical field of oil exploration in recent years.Shale oil with medium and low maturity has huge resource potential,and technological recoverable resources of(70?90)billion tons,making it a strategic alternative resource of oil industry.However,economic development of this type of shale oil needs in-situ conversion technology breakthroughs.Continental shale oil is an inevitable choice in the process of Chinese continental petroleum exploration from"outside source"to"inside source".Making breakthroughs in the core technologies such as"sweet area"evaluation and optimization,horizontal well volume fracturing and in-situ conversion technology and equipment is the key to realizing scale development of continental shale oil economically.